Can't get add-on Confluence Cloud developer tutorial working

I am attempting to follow the steps at:

During “Step 4: Test your app” I am unable to see the Hello World Macro using /hello while the node server is running. I can see in the Manage Apps page that the app has been installed. If I instead try to add the macro using the ‘+’ > View More, I can see the “Hello World Macro” but after adding it, all I get is “App is not responding”.

The example output provided in the tutorial lists 3 GET rows for /macro…, /css and /js that I also don’t see.